package com.lagou.client;

import com.lagou.component.encoder.RpcRequestJsonEncoder;
import com.lagou.protocol.RpcRequest;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;

public class RpcConsumer {

    /**
     * 创建线程池对象
     */
    private static ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    private static UserClientHandler userClientHandler;

    private static AtomicInteger REQUEST_ID_COUNTER = new AtomicInteger(0);

    /**
     * 创建一个代理对象
     * UserService
     * sayHello
     * are you ok?
     */
    public Object createProxy(final Class<?> serviceClass, final String methodName) {
        //借助JDK动态代理生成代理对象
        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class<?>[]{serviceClass}, new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                //（1）调用初始化netty客户端的方法
                if (userClientHandler == null) {
                    initClient();
                }

                RpcRequest rpcRequest = new RpcRequest();
                rpcRequest.setRequestId(String.valueOf(REQUEST_ID_COUNTER.getAndIncrement()));
                rpcRequest.setClassName(serviceClass.getSimpleName());
                rpcRequest.setMethodName(methodName);

                Class[] paramTypes = new Class[args.length];
                for (int i = 0; i < args.length; i++) {
                    Object arg = args[i];
                    paramTypes[i] = arg.getClass();
                }
                rpcRequest.setParameterTypes(paramTypes);
                rpcRequest.setParameters(args);

                // 设置参数
                userClientHandler.setPara(rpcRequest);

                // 去服务端请求数据
                return executor.submit(userClientHandler).get();
            }
        });

    }


    /**
     * 2.初始化netty客户端
     */
    public static void initClient() throws InterruptedException {
        userClientHandler = new UserClientHandler();

        EventLoopGroup group = new NioEventLoopGroup();

        Bootstrap bootstrap = new Bootstrap();
        bootstrap.group(group)
                .channel(NioSocketChannel.class)
                .option(ChannelOption.TCP_NODELAY, true)
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ChannelPipeline pipeline = ch.pipeline();
                        pipeline.addLast(new RpcRequestJsonEncoder());
                        pipeline.addLast(new StringDecoder());
                        pipeline.addLast(userClientHandler);
                    }
                });

        bootstrap.connect("127.0.0.1", 8990).sync();

    }


}
